1. Technical Field
The present invention relates to an electronic component having electrical connecting portions such as solder bumps or electrodes (lands, for example) exemplified by a solder bump component of a BGA (Ball Grid Array) type semiconductor component package (referred to as a BGA component hereinafter) represented by a CSP (Chip Size Package) or an electronic component such as QFP in forming an electronic circuit and relates to the mounting method and apparatus thereof.
2. Description of Related Art
In recent years, personal computers, portable telephones, information communications devices, multimedia electronic equipment, and the like have been compacted and provided with improved functions. Further, the electronic components and printed boards constituting electronic circuits have been made to have higher densities and finer constructions due to higher frequencies, and the mounting of components having a plurality of pins go mainstream in conformity to high-density circuits of QFP (Quad Flat Package) and the like. However, on increasing the density, the lead pitch of the connecting portions has been reduced in stages, for example, from 0.5 mm through 0.3 mm to the extent of 0.2 mm, for which the mounting method and manufacturing method themselves have become hard to be achieved.
It is further demanded for electronic circuits to cope with the reduction in size, higher functions, and higher frequencies, and this leads to a great desire to effectively mount printed boards with electronic components having solder bumps such as BGA (Ball Grid Array) represented by bare ICs of narrower lead pitches and CSP (Chip Size Package) and the like.
FIG. 15 is a front view schematically showing the land patterns of a QFP component and BGA components having solder bumps on a printed board. FIG. 16A is a sectional view of the BGA component having these solder bumps and the printed board to be mounted with the BGA component, while FIG. 16B is a bottom view of the BGA component. In FIG. 15 and FIGS. 16A and 16B, reference numeral 1 denotes a printed board, 2 BGA component connecting lands, 2xe2x80x2 QFP connecting lands, 3 BGA component use board recognition marks, 3xe2x80x2 QFP use board recognition marks, 4 BGA component land patterns, 4xe2x80x2 a QFP land pattern, 5 a BGA component that serves as an electronic component, 6 a bump-shaped solder connecting portions (referred to as BG connecting portions hereinafter) that serves as portions to be electrically connected via solder bumps 7 to the circuit board electrodes, and 7 the solder bumps.
There is further known a component mounting apparatus as shown in the partially see-through perspective view of FIG. 17 as a principal implement of a mounting position determining method of the component mounting apparatus. In FIG. 17, reference numeral 10 denotes a component mounting apparatus, 11 an operating section, 12 a control section, 13 a mounting head, 14 a mounting table, 15 a conveyance rail, and 16 a component supplying section. The component mounting apparatus 10 shown in FIG. 17 is mounted with the sliding component supplying section 16 and an X-Y table that serves as the mounting table 14 for holding and positioning a printed board.
FIG. 18 is a partially see-through perspective view of another component mounting apparatus. In FIG. 18, reference numeral 10 denotes a component mounting apparatus, 11 an operating section for executing inputting and outputting for the execution of a mounting program of NC data or the like, 12 a control section for controlling the whole mounting process by recognition, calculation, and various instructions in mounting components, 13 a mounting head for holding the component to be mounted and mounting the component on the board, 13a a component inspecting section for inspecting the component held by the mounting head, 13b a board recognizing section for recognizing the position of the board conveyed to the board mounting table, 14 a mounting table for holding the board that is conveyed so as to be mounted with the component, 15 a conveyance rail for conveying the board with respect to the mounting table 14, 16 a component supplying section for supplying the component to be mounted, 16xe2x80x2 a parts tray that serves as an example of the component supplying section 16 in which components are arranged in a matrix form, 16a a parts cassette that serves as an example of the component supplying section 16 in which tape components are stored, 16b a bulk cassette that serves as an example of the component supplying section 16 in which components are stored, and 16c a parts tray storing section for storing the parts tray 16xe2x80x2. As shown in FIG. 18, there is known the mounting apparatus having the above construction, which operates to pick up an electronic component from the component supplying section 16 by the mounting head 13 and move the electronic component held by the mounting head 13 to the mounting table 14 while recognizing the posture and so on of the electronic component held by the mounting head 13, thereafter moving the electronic component by the mounting head 13 to the mounting position on the board 1 held on the mounting table 14 and subsequently lowering the mounting head 13 to execute the mounting of the electronic component in the mounting position of the board 18. It is to be noted that the BGA components are generally stored in the parts tray 16xe2x80x2 or the parts cassette 16a. The components can be mounted in and supplied from the tape-shaped parts cassette 16a, the bulk cassette 16b for components stored in a scattered form, the component supply section 16xe2x80x2 that concurrently serves as a plate-shaped parts tray, and the like, which serve as a removable component set for continuously supplying the components. Further, the printed board 1 is conveyed onto the mounting table 14 for mounting the components, by the conveyance rails 15, and subjected to a specified mounting process, and thereafter the printed board 1 is conveyed to the outside by the conveyance rails 15.
Further, FIG. 19 shows a sectional view showing the mounting of a BGA component by the component mounting apparatus shown in FIG. 18. Solder paste 7xe2x80x2 is provided on the connection lands 2 of the printed board 1 shown in FIG. 16A, and the BGA component 5 supplied from the component supplying section 16 is held by the mounting head 13 and moved to a specified position of the printed board 1. Thereafter, as shown in FIG. 19, the BGA component 5 held by the mounting head 13 is depressed in the direction of the arrow D so as to connect the solder bumps 7 of the BG connecting portions 6 to the connection lands 2 of the printed board 1 via the solder paste 7xe2x80x2 provided on the lands 2.
The operation of the prior art electronic component mounting apparatus will be described with reference to FIG. 16. This component mounting apparatus 10 is to mount an electronic component (BGA component 5) on the printed board 1. On the component supplying section 16 or 16xe2x80x2 is provided a cassette or a tray conforming to the type of the electronic component necessary for actual mounting by the component mounting apparatus 10. Each cassette or tray supplies a component that is needed every moment.
The component necessary for the mounting is taken out by the mounting head 13, and the electronic component is subjected to component recognition executed by the component inspecting section 13a and to quality check (good-or-bad decision) and retention posture check of the component by comparing the result of recognition with the shape preparatorily stored in the control section. On the basis of the result of this check, posture correction data of the component is stored in the control section in a correction process as needed, and then, the target mounting land position on the printed board 1 is recognized by the board recognizing section 13b. Thereafter, the electronic component held by the mounting head is positioned in the recognized mounting land position, and the electronic component is mounted on the board with a certain accuracy after executing posture correction based on the posture correction data and board position dislocation data previously stored in the control station.
In mounting the BGA component 5 having the solder bumps 7, which is an electronic component as shown in FIGS. 16A and 16B, between the connection lands 2 on the printed board 1 and the BG connecting portions 6 of the connecting surface of the BGA component 5 cannot generally be checked for the confirmation of the component being mounted within a proper range since it is hidden behind the BGA component 5 in appearance after the component is mounted.
Therefore, according to the prior art mounting method or the mounting apparatus, as an example of the electronic component position detecting method for securing the mounting position and the soldering quality in mounting the BG connecting portions 6 on the board, the mounting is executed by detecting the position of the component based on the contour of the whole component through image recognition as disclosed in the Japanese Laid-Open Patent Publication No. 6-288732 or based on the state of the partial or total arrangement of the BG connecting portions 6 and the connecting surface.
However, according to the mounting method and apparatus of the component having solder bumps constructed as above, the actual positions of the BG connecting portions become uncertain in the case of only the contour, or much time is required in executing the positional detection of the BG connecting portions one by one. As a result, the time of recognition required for the positional detection of the BG connecting portions themselves influences the time of the mounting cycle. Therefore, the positional detection has been partially executed instead of executing the positional detection of all the BG connecting portions, meaning that the processing has been executed without correct positional detection.
With regard to the arrangement pattern of the BG connecting portions in the connecting surface of the BGA component, a variety of patterns based on the matrix pattern as shown in FIG. 20A including variations such as a pattern in which the BG connecting portions are partially not existing, as shown in FIG. 20B through FIG. 20J, must be recognized. Since such a variety of patterns are requested to be recognized, the partial positional detection of the BG connecting portions solely becomes incorrect. The state of partial or whole arrangement of the BG connecting portions is subjected to a recognition process such that the contour is set in the position detecting process since no definite reference point for executing image processing exists.
Furthermore, in order to recognize and check the correct position and pattern, a greater processing storage capacity, a complicated algorithm, and so on for the check are needed to consume much processing time, and the time required for the processing exerts a great influence on the time of the mounting cycle. Particularly in the case of the BGA components having irregular patterns as shown in FIGS. 20H through 20J, more complicated processing and memory resources are required, and this has led to the problem that the positional detection and the arrangement pattern recognition are practically difficult.
The present invention solves the aforementioned prior art problems and has the object of providing an electronic component as well as mounting method and apparatus of the component that are able to recognize the state of arrangement of the whole electrical connecting portions easily and correctly at high speed in mounting the electronic components such as: a BGA component represented by, for example, CSP having solder bumps for forming an electronic circuit; or a QFP component having no solder bump for forming an electronic circuit and satisfies a reliable component mounting quality of a high productivity.
The present invention is constructed as follows to achieve the aforementioned object.
According to a first aspect of the present invention, there is provided an electronic component to be mounted on a printed board, characterized by comprising:
a plurality of electrical connecting portions provided on an electrical connecting surface of the electronic component and the printed board; and a reference mark that serves as a reference of arrangement positions of the electrical connecting portions.
According to a second aspect of the present invention, there is provided an electronic component according to the first aspect, characterized in that the reference mark of the electronic component is provided on the electrical connecting surface side facing a mounting position on the printed board.
According to a third aspect of the present invention, there is provided an electronic component according to the first aspect, characterized in that the reference mark of the electronic component is provided on the opposite side of the electrical connecting surface that faces the mounting position on the printed board.
According to a fourth aspect of the present invention, there is provided an electronic component according to the second or third aspect, characterized in that the reference mark of the electronic component is a projection peculiar to the electronic component, or a print.
According to a fifth aspect of the present invention, there is provided an electronic component according to the second or third aspect, characterized in that the reference mark of the electronic component includes at least one reference mark obtained by coding information concerned with the electronic component.
According to a sixth aspect of the present invention, there is provided an electronic component according to the fifth aspect, characterized in that the information of the reference mark is discrimination information of the electronic component expressed by a two-dimensional bar code.
According to a seventh aspect of the present invention, there is provided an electronic component according to the fifth aspect, characterized in that the information of the reference mark is information concerned with a state in which the electrical connecting portions are formed.
According to an eighth aspect of the present invention, there is provided an electronic component according to any one of the first through seventh aspects, wherein the reference mark is located in a corner portion of the electronic component.
According to a ninth aspect of the present invention, there is provided an electronic component according to any one of the first through eighth aspects, the reference mark is formed on the electronic component simultaneously with the electrical connecting portions.
According to a tenth aspect of the present invention, there is provided an electronic component according to any one of the first through ninth aspects, wherein the electrical connecting portions are solder bumps.
According to an eleventh aspect of the present invention, there is provided an electronic component according to any one of the first through ninth aspects, wherein the electrical connecting portions are lands.
According to a twelfth aspect of the present invention, there is provided an electronic component mounting method for taking out an electronic component from a component supply section and mounting the electronic component in a mounting position on a printed board, comprising:
a recognizing process for recognizing a reference mark that is provided on the electronic component to be mounted and serves as a reference of arrangement positions of electrical connecting portions provided on an electrical connecting surface of the electronic component and the printed board; and
a quality checking or correcting process for executing quality check of the electronic component or executing positional correction in a mounting stage according to a result of recognition,
whereby the mounting of the electronic component that has passed through the quality checking or correcting process is executed.
According to a thirteenth aspect of the present invention, there is provided an electronic component mounting method for taking out an electronic component from a component supply section and mounting the electronic component in a mounting position on a printed board, comprising:
a first recognizing process for recognizing a reference mark that is provided on the electronic component to be mounted and serves as a reference of arrangement positions of electrical connecting portions provided on an electrical connecting surface of the electronic component and the printed board;
a second recognizing process for recognizing a recognition mark of a target mounting position on the printed board; and
a quality checking and correcting process for executing quality check of the electronic component and executing positional correction in a mounting stage according to results of recognition of the first recognizing process and the second recognizing process,
whereby the mounting of the electronic component that has passed through the quality checking and correcting process is executed.
According to a fourteenth aspect of the present invention, there is provided an electronic component mounting method according to the twelfth or thirteenth aspect, characterized in that the quality check of the electronic component to be mounted includes a component inspecting process for checking the electronic component by a state of formation of the electrical connecting portions recognized based on a relative position with respect to the reference mark of the electronic component.
According to a fifteenth aspect of the present invention, there is provided an electronic component mounting method according to any one of the twelfth through fourteenth aspects, characterized in that at least one of a plurality of recognition marks of the target mounting position on the printed board is discrimination information of the electronic component to be mounted, the information being expressed by a two-dimensional bar code obtained by coding information.
According to a sixteenth aspect of the present invention, there is provided an electronic component mounting method according to any one of the twelfth through fifteenth aspects, wherein the reference mark of the electronic component includes at least one reference mark obtained by coding information concerned with the state of formation of the electrical connecting portions, and the electronic component that is determined to be defective through the quality checking process is processed on the basis of the information of the reference mark concerned with the state of formation of the electrical connecting portions.
According to a seventeenth aspect of the present invention, there is provided an electronic component mounting method according to any one of the twelfth through fourteenth aspects, wherein the reference mark is formed on the electronic component simultaneously with the electrical connecting portions.
According to an eighteenth aspect of the present invention, there is provided an electronic component mounting method according to any one of the twelfth through seventeenth aspects, wherein the electrical connecting portions are solder bumps.
According to a nineteenth aspect of the present invention, there is provided an electronic component mounting method according to any one of the twelfth through seventeenth aspects, wherein the electrical connecting portions are lands.
According to a twentieth aspect of the present invention, there is provided an electronic component mounting apparatus characterized by comprising:
a component supply section of the electronic component defined in any one of the first through eleventh aspects;
a mounting head for moving the electronic component from the component supply section to a mounting position and mounting the electronic component on the printed board;
a mounting table on which the printed board to be mounted with the electronic component is placed;
a component inspecting section for recognizing the reference mark of the electronic component to be mounted; and
a control section for executing quality check or positional correction in the mounting stage of the electronic component according to a result of recognition.
According to a twenty-first aspect of the present invention, there is provided an electronic component mounting apparatus characterized by comprising:
a component supply section of the electronic component defined in any one of the first through eleventh aspects;
a mounting head for moving the electronic component from the component supply section to a mounting position and mounting the electronic component on the printed board;
a mounting table on which the printed board to be mounted with the electronic component is placed;
a component inspecting section for recognizing the reference mark of the electronic component to be mounted;
a board recognizing section for recognizing a recognition mark of the mounting position of the printed board; and
a control section for executing quality check or positional correction in the mounting stage of the electronic component according to a result of recognition.
According to a twenty-second aspect of the present invention, there is provided an electronic component mounting apparatus according to the twentieth or twenty-first aspect, wherein the reference mark obtained by coding information provided for the electronic component to be mounted is recognized by also using either the component inspecting section that recognizes the reference mark provided for the electronic component or the recognizing section that recognizes the recognition mark of the target mounting position on the printed board.
According to a twenty-third aspect of the present invention, there is provided an electronic component mounting apparatus according to any one of the twentieth through twenty-second aspects, wherein the reference mark is formed on the electronic component simultaneously with the electrical connecting portions.
According to a twenty-fourth aspect of the present invention, there is provided an electronic component mounting apparatus according to any one of the twentieth through twenty-third aspects, wherein the electrical connecting portions are solder bumps.
According to a twenty-fifth aspect of the present invention, there is provided an electronic component mounting apparatus according to any one of the twentieth through twenty-third aspects, wherein the electrical connecting portions are lands.
According to the above construction, the state of arrangement positions and the shapes of the whole solder bumps can be confirmed by providing the reference mark on the connecting surface side of the solder bump component to be mounted on the printed board.
Furthermore, by providing the reference mark on the surface opposite from the connecting surface of the solder bump component to be mounted on the printed board, the positional detection can be confirmed in appearance before or after the mounting.
Furthermore, the same operation is owned by the projection peculiar to the solder bump component or the print, and with the expression of the reference mark or the two-dimensional bar code obtained by coding information, the information for the mounting can be reliably obtained according to the discrimination information of each component.
The recognizing process for recognizing the reference mark provided on the electronic component to be mounted and the correcting process for executing the quality check of the electronic component or the positional correction in the mounting stage according to the result of the recognition are included to allow reliable solder bump component mounting to be executed.
By executing the first recognizing process for recognizing the reference mark provided on the electronic component to be mounted, the second recognizing process for recognizing the recognition mark of the target mounting position on the printed board, and the quality check or the positional correction according to both the results of the recognition of the first recognizing process and the second recognizing process, more reliable solder bump component mounting can be executed.
The quality check of the electronic component to be mounted includes the component inspecting process for checking the electronic component by the state of formation of the solder bumps recognized based on the relative position of the solder bumps with respect to the reference mark of the electronic component, and this process enables the confirmation of the shape states of the dislocation, solder dropout, insufficient solder amount, and so on of the solder bumps prior to the mounting.
The recognition of the reference mark obtained by coding the information is achieved while sharing either the process of recognizing the reference mark provided for the electronic component to be mounted or the process of recognizing the recognition mark of the target mounting position on the printed board, so that a structure that necessitates no separate detector for use in the electronic component inspecting and mounting position recognizing process can be provided.
Furthermore, at least one of the recognition marks on the printed board is the discrimination information of the component to be mounted expressed by the two-dimensional bar code obtained by coding the information, so that the confirmation of the electronic component to the mounting position can be executed to allow the elimination of faulty mounting.